[Retracted] Spare Parts Stocking Decision Strategy and Service Logistics Cost Optimization of Two-Echelon Service Logistics System considering Multifailure Mode

Table 1

Model variables.

	Item number, ,
	Site number, Depot: , Base:
	Single cycle demand mean value of item i at site j
	Single cycle demand mean value of item i’s hard failure mode
	Single cycle demand mean value of item i’s soft failure mode
	Repairing time of item i at site j
	Order and ship time of item i from the Depot to the site j
	Price of item
	Level of stocking of item i at site j